bank_proj.rb

# Tip: If you name your gist foo.rb it will highlight the code as Ruby.
class Account
  # Two things here. First you never use the reader methods you define here.
  # You can either refactor the code to use them [see other gist]
  # or just remove them and keep using the instance variables.
  # Second, usually Rubyists [we have a name!] group class-level code 
  # like attr_reader or defining constants apart from the method definitions
  # with newlines. Multiple calls of similar types [like another attr_reader here]
  # would be back-to-back [no newlines] though. Just a readability thing.
  attr_reader :name, :balance

  def initialize(name, balance=100)
    @name = name
    @balance = balance
  end
    
# I like to outdent private and protected declarations with a newline after. Readability again.
private

  def pin
    @pin = 1234
  end

  def pin_error
    "Invalid Pin"
  end
    
# Instead of having public methods down here, most Rubyists just put all the public methods at the top
# where you have initialize defined. This is totally valid. Just a style tip you will see.
# Methods are public by default so usually people just leave them in that public area
# and only switch to private/protected at the end of the class definition.
public

  def display_balance(pin_number)
    puts pin_number == pin ? "Balance: $#{@balance}." : pin_error
  end
    
  def withdraw(pin_number, amount)
    if pin_number == pin
      @balance -= amount
      puts "Withdrew $#{amount}. New balance: $#{@balance}."
    else
      pin_error
    end
  end
    
  def deposit(pin_number, amount)
    if pin_number == pin
      @balance += amount
      puts "$#{amount} successfully despoited into your account, #{name}. New balance: $#{@balance}"
    else
      pin_error
    end
  end
end

class Machine
  def initialize
    startup
  end
  
  def startup
    login = [1, 2]
    puts "+--------------------+"
    puts "|Welcome to your bank|"
    puts "+--------------------+"
    puts "| 1-login   2-create |"
    puts "+--------------------+"
    puts " "
    print "..."
    # Don't be afraid of making whatever strtp is clear by naming the variable clearly.
    # Ruby values clarity and [wait for it...] readability.
    strtp = gets.chomp.to_i
    if strtp == login[0]
      user_login
    else
      "Error"
    end
  end
  
  def user_login
    print "Username: " 
    @user_name = gets.chomp
    @account = Account.new(@user_name, 1_000_000)
    print "Enter PIN: "
    @user_pin = gets.chomp.to_i
    user_control
  end
  
  def user_control
    control = [1, 2, 3]
    puts "Welcome, #{@user_name} what would you like to do?"
    puts "1) Check Balance"
    puts "2) Withdraw"
    puts "3) Deposit"
    print "... "
    # Another place where the variable seems... not Rubyish.
    # user_control is better. Anything clear though.
    # Abbreviations are for PHP and Perl. ;)
    usrcntrl = gets.chomp.to_i
    # Hint: You want to read about switch statements. No spoiler. ;)
    if usrcntrl == control[0]
      @account.display_balance(@user_pin)
    elsif usrcntrl == control[1]
      print "Enter amount to withdraw($): "
      w_amount = gets.chomp.to_i
      @account.withdraw(@user_pin, w_amount)
    elsif usrcntrl == control[2]
      print "Enter amount to deposit($): "
      d_amount = gets.chomp.to_i
      @account.deposit(@user_pin, d_amount)
    else
      "Error"
    end
  end
end

your_bank = Machine.new